1. Field of the Invention
The present invention relates to a dryer having an improved arrangement of heating coils.
2. Discussion of the Related Art
Generally, a laundry dryer is an apparatus for drying an object to be dried by blowing hot air generated from a heater assembly into a space holding the object. The dryer is equipped with a drying function. Yet, there is a washing machine equipped with the drying function as well.
A drum is rotatably provided in the dryer to hold the object to be dried. As the drum rotates, the object in the drum is lifted up to fall. In doing so, the dry hot air discharged from the heater assembly is blown into the drum to dry the falling object.
A heater assembly according to a related art consists of a heater case, a plate, an upper coil array, and a lower coil array.
The heater case is provided in the dryer, and the plate is provided parallel between air inlet and outlet of the heater case. The upper coil array is plurally arranged in a row over the plate to be heated in one body, and the lower coil array is plurally arranged in a row under the plate to be heated in one body. It is controlled that one of the upper and lower coil arrays emits heat or that both of the upper and lower coil arrays emit heat.
An operation of the related art dryer is explained as follows.
First of all, in the heater assembly, when power is applied to both of the upper and lower coil arrays, coils of the upper and lower coil array generate heat. Air flowing over the plate passes through the coils of the upper coil array to be heated and is then discharged. Air flowing under the plate passes through the coils of the lower coil array to be heated and is then discharged.
Meanwhile, if the power is applied to the upper coil array only, the air flowing over the plate is heated by the coils of the upper coil array to be discharged later. Yet, the air flowing under the plate fails to be heated.
In the related art heater assembly of the dryer, if the power is applied to one of the upper and lower coil arrays, temperature rise is concentrated on the heater case in the vicinity of the turned-on coil array only. The air around the turned-off coil array fails to be heated and is then discharged. Hence, drying performance is reduced.